Utah's basement — Beaver Dam Wash is state's lowest elevation

BEAVER DAM WASH, Washington County — St. George isn't the hottest place in Utah, nor does it have the lowest elevation. Those superlatives belong to the Beaver Dam Wash in the extreme southwest corner of the state, at the Utah-Arizona state line.

Welcome to Utah's basement, in the Beaver Dam Wash, where an environment exists unlike anywhere else in the Beehive State. It's the Mojave Desert, where Joshua trees, blackbrush, creosote, yucca and other southern desert plants rule in an ovenlike environment this time of year.

Kings Peak is Utah's highest elevation at 13,538 feet above sea level, but at Beaver Dam Wash — 288 air miles away — the elevation dips more than two miles below Kings and is almost 600 feet lower than the city of St. George, located some 23 miles to the northeast.

The majority of sources out there — Internet and books — have Utah's lowest elevation all wrong. Utah's lowest point isn't 2,350 feet above sea level, as is commonly listed by Utah tourist sources. Nor is it an even 2,000 feet, as some other sources list.

Utah's lowest elevation here is "probably" 2,178 feet above sea level.

(In contrast, St. George has an average elevation of 2,800 feet and Salt Lake City's Temple Square is 4,327 feet above sea level.)

That's according to Mark Milligan, a geologist with the Utah Geological Survey, who found that quadrangle maps show the lowest spot is found in an area bounded by 2,160-foot and 2,180-foot contour lines.

"The border is much closer to the 2,180 contour and thus agrees with an elevation of 2,178 feet," he wrote in an e-mail to the Deseret Morning News.

He found that even though the USGS Geographic Names Information also lists Utah's lowest elevation at 2,178 feet, in the same entry it uses the even 2,000-foot number as the state's least elevation, too.

Milligan believes 2,178 is as close an estimate to the low elevation as is possible. Since the Beaver Dam Wash is an area prone to flooding, its elevation can change.

"Of course, it is possible erosion may have recently lowered this portion of the wash," Milligan reported in his e-mail. "The precipitation that caused the 2005 flooding in St. George presumably caused flooding in the Beaver Dam Wash.

"I have not been there recently enough to remember what the bottom of the wash looks like in that area. So I would not even dare an educated guess as to whether to expect much erosion there from such floods."